diff --git a/src/algorithms/libs/galileo_e6_signal_replica.cc b/src/algorithms/libs/galileo_e6_signal_replica.cc
index d0e93fda7..4b84cad40 100644
--- a/src/algorithms/libs/galileo_e6_signal_replica.cc
+++ b/src/algorithms/libs/galileo_e6_signal_replica.cc
@@ -235,6 +235,10 @@ std::string galileo_e6_c_secondary_code(int32_t prn)
 {
     std::string dest(static_cast<size_t>(GALILEO_E6_C_SECONDARY_CODE_LENGTH_CHIPS), '0');
     const uint32_t prn_ = prn - 1;
+    if ((prn < 1) || (prn > 50))
+        {
+            return dest;
+        }
     uint32_t index = 0;
     for (size_t i = 0; i < GALILEO_E6_C_SECONDARY_CODE_STR_LENGTH; i++)
         {
diff --git a/src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking.cc b/src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking.cc
index 92f11ded9..d0f9f550c 100644
--- a/src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking.cc
+++ b/src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking.cc
@@ -730,7 +730,7 @@ void dll_pll_veml_tracking::start_tracking()
         {
             if (d_trk_parameters.track_pilot)
                 {
-                    d_secondary_code_string = galileo_e6_c_secondary_code(d_acquisition_gnss_synchro->PRN - 1);
+                    d_secondary_code_string = galileo_e6_c_secondary_code(d_acquisition_gnss_synchro->PRN);
                     galileo_e6_b_code_gen_float_primary(d_data_code, d_acquisition_gnss_synchro->PRN);
                     galileo_e6_c_code_gen_float_primary(d_tracking_code, d_acquisition_gnss_synchro->PRN);
                     d_Prompt_Data[0] = gr_complex(0.0, 0.0);